The present invention relates to a boring head for internal machining of bores in workpieces comprising at least one insert holder and an operating means adapted to, by means of a first abutting surface, cooperate with a second abutting surface on the insert holder for radial adjustment thereof. Specifically, the invention relates to the type of boring heads used for skiving, usually called skiving tools, of for instance tubes, which are to be provided with a bearing surface for use in hydraulic cylinders.
During machining operations of the above type the boring head is fed axially through the workpiece. The boring head can be provided with one or several guide pads adapted to support and guide the boring head along the bore in the workpiece. Usually, the boring head is combined with a tool for roller burnishing for finishing the internal surface of the bore to be produced. This burnishing operation is carried out when the skiving tool is returned axially to its initial position before starting a new processing cycle. Before starting the burnishing operation the cutting inserts on the boring head have to be retracted in order not to cause damages on the internal surface of the bore.
In boring heads of the above type it has been proposed, for instance in EP No. 0016744, to arrange the insert holders radially adjustably for purposes of making possible roller burnishing without removing the cutting inserts from the boring head. The object of the present invention is to provide a simple and reliable mechanism in such boring heads for the radial adjustment of the insert holders.
Another object of the invention is to provide improved means for the initial radial positioning of the cutting inserts.
A further object of the invention is to provide an improved cutting insert to be used in connection with roller burnishing.
These and other objects of the invention are attained by giving the invention the characterizing features stated in the appended claims.